package com.fy.utils;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.rendering.PDFRenderer;
import org.fit.pdfdom.PDFDomTree;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import sun.misc.BASE64Encoder;

import javax.imageio.ImageIO;
import javax.xml.parsers.ParserConfigurationException;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;

/**
 * @Description: PDF转Html工具类
 **/
public class PdfConvertHtmlUtil {

    /**
     * 日志对象
     */
    private static Logger logger = LoggerFactory.getLogger(PdfConvertHtmlUtil.class);

    public static void generateHTMLFromPDF(String filename) throws IOException, ParserConfigurationException {
        PDDocument pdf = PDDocument.load(new File(filename));
        Writer output = new PrintWriter("pdf.html", "utf-8");
        new PDFDomTree().writeText(pdf, output);
        output.close();
    }

    /**
     * PDF文档流转Png
     * @param pdfFileInputStream
     * @return BufferedImage
     */
    public static BufferedImage pdfStreamToPng(InputStream pdfFileInputStream){
        PDDocument doc = null;
        PDFRenderer renderer = null;
        try {
            doc = PDDocument.load(pdfFileInputStream);
            renderer = new PDFRenderer(doc);
            int pageCount = doc.getNumberOfPages();
            BufferedImage image = null;
            for (int i = 0; i < pageCount; i++) {
                if (image != null) {
                    image = combineBufferedImages(image, renderer.renderImageWithDPI(i, 144));
                }

                if (i == 0) {
                    image = renderer.renderImageWithDPI(i, 144); // Windows native DPI
                }
                // BufferedImage srcImage = resize(image, 240, 240);//产生缩略图

            }
            return combineBufferedImages(image);
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                if(doc != null){doc.close();}
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    /**
     *BufferedImage拼接处理，添加分割线
     * @param images
     * @return BufferedImage
     */
    public static BufferedImage combineBufferedImages(BufferedImage... images) {
        int height = 0;
        int width = 0;
        for (BufferedImage image : images) {
            //height += Math.max(height, image.getHeight());
            height += image.getHeight();
            width = image.getWidth();
        }
        BufferedImage combo = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
        Graphics2D g2 = combo.createGraphics();
        int x = 0;
        int y = 0;
        for (BufferedImage image : images) {
            //int y = (height - image.getHeight()) / 2;
            g2.setStroke(new BasicStroke(2.0f));// 线条粗细
            g2.setColor(new Color(193, 193, 193));// 线条颜色
            g2.drawLine(x, y, width, y);// 线条起点及终点位置

            g2.drawImage(image, x, y, null);
            //x += image.getWidth();
            y += image.getHeight();

        }
        return combo;
    }
    /**
     * 通过Base64创建HTML文件并输出html文件
     * @param base64
     * @param htmlPath html保存路径
     */
    public static void createHtmlByBase64(String base64,String htmlPath) {
        StringBuilder stringHtml = new StringBuilder();
        PrintStream printStream = null;
        try {
            // 打开文件
            printStream = new PrintStream(new FileOutputStream(htmlPath));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }
        // 输入HTML文件内容
        stringHtml.append("<html><head>");
        stringHtml.append("<meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\">");
        stringHtml.append("<title></title>");
        stringHtml.append("</head>");
        stringHtml.append(
                "<body style=\"\r\n" + "    text-align: center;\r\n" + "    background-color: #C1C1C1;\r\n" + "\">");
        stringHtml.append("<img src=\"data:image/png;base64," + base64 + "\" />");
        stringHtml.append("<a name=\"head\" style=\"position:absolute;top:0px;\"></a>");
        //添加锚点用于返回首页
        stringHtml.append("<a style=\"position:fixed;bottom:10px;right:10px\" href=\"#head\">回到首页</a>");
        stringHtml.append("</body></html>");
        try {
            // 将HTML文件内容写入文件中
            printStream.println(stringHtml.toString());
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            if(printStream != null){printStream.close();}
        }

    }

    /**
     * bufferedImage 转为 base64编码
     * @param bufferedImage
     * @return
     */
    public static String bufferedImageToBase64(BufferedImage bufferedImage) {
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        String pngBase64 = "";
        try {
            // 写入流中
            ImageIO.write(bufferedImage, "png", byteArrayOutputStream);
            // 转换成字节
            byte[] bytes = byteArrayOutputStream.toByteArray();
            BASE64Encoder encoder = new BASE64Encoder();
            // 转换成base64串 删除 \r\n
            pngBase64 = encoder.encodeBuffer(bytes).trim()
                    .replaceAll("\n", "")
                    .replaceAll("\r", "");
        } catch (IOException e) {
            e.printStackTrace();
        }
        return pngBase64;
    }

    public static void main(String[] args) {
        File file = new File("D:\\tmp\\123.pdf");
        String htmlPath = "D:\\tmp\\123.html";
        InputStream inputStream = null;
        BufferedImage bufferedImage = null;
        try {
            inputStream = new FileInputStream(file);
            bufferedImage = pdfStreamToPng(inputStream);
            String base64Png = bufferedImageToBase64(bufferedImage);
            createHtmlByBase64(base64Png,htmlPath);

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }finally {
            try {
                if(inputStream != null){inputStream.close();}
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}